Rotary cartridge seal with internal face-sealing surfaces

Abstract

A cartridge seal for sealing a space between a housing and a rotatable shaft includes a rotary sealing member having an inner surface defining a bore for receiving the shaft and a circular outer flange extending radially outwardly from and circumferentially about a central axis, the outer flange having a radial sealing surface. A static seal assembly is disposed about the rotary member and includes an annular casing coupleable with the housing and an annular static sealing member disposed within the casing and having a radial sealing surface engageable with the rotary member sealing surface to form a sealing interface. A biasing member axially biases at least a portion of the static sealing member toward the rotary member flange. An annular collar is disposed within the casing and axially retains the rotary member within the casing such that the seal assembly is mountable on a shaft as a single unit.

We claim: 
     
       1. A cartridge seal for sealing a space between a housing having a bore and a shaft disposed at least partially within the housing bore and rotatable about a central axis, the cartridge seal comprising:
 a rotary sealing member having an inner circumferential surface defining a bore for receiving a portion of the shaft and a generally circular outer flange extending radially outwardly from and circumferentially about the central axis, the outer flange having a generally radial sealing surface; and 
 a static seal assembly disposed about the rotary sealing member and including a generally annular casing coupleable with the housing, a generally annular static sealing member disposed within the casing and having a generally radial sealing surface sealingly engageable with the rotary member sealing surface so as to form a primary sealing interface, a biasing member configured to axially bias at least a portion of the static sealing member generally toward the rotary member flange, and a generally annular collar disposed at least partially within the casing, having an axial portion disposed about the rotary sealing member and being configured to axially retain the rotary member within the casing such that the seal assembly is mountable on a shaft as a single unit. 
 
     
     
       2. The cartridge seal as recited in  claim 1  wherein the rotary member flange is formed of a metallic material, the rotary member sealing surface has a hardness of at least 45 as measured on the Rockwell C scale (45 HRC), and at least a portion of the seal member providing the sealing surface is formed of carbon reinforced polymer. 
     
     
       3. The cartridge seal as recited in  claim 2  wherein the rotary member is formed of stainless steel having a hardness within a range of about 45 HRC to about 50 HRC, and the seal member is formed of a wear resistant polymer. 
     
     
       4. The cartridge seal as recited in  claim 1  wherein the rotary sealing member is frictionally engageable with the shaft so as to retain the rotary member at about a desired axial position on the central axis. 
     
     
       5. The cartridge seal as recited in  claim 4  further comprising at least one elastomeric ring disposeable within the bore of the rotary member and configured to frictionally engage with an outer surface of the shaft so as to axially retain the rotary member. 
     
     
       6. The cartridge seal as recited in  claim 1  wherein the static sealing member has an inner circumferential surface, an annular groove extending radially outwardly from the inner surface so as to define a pair of axially spaced-apart radial wall sections, one of two radial wall sections being a sealing wall section disposeable against the rotary member flange and providing at least a portion of the static sealing member radial sealing surface, the biasing member being disposed within the groove and configured to bias the sealing wall section toward the rotary member flange. 
     
     
       7. The cartridge seal as recited in  claim 6  wherein the static sealing member has a plurality of annular projections extending generally axially from the sealing surface and engageable with the rotary member sealing surface. 
     
     
       8. The cartridge seal as recited in  claim 6  wherein the biasing member includes a generally annular V-spring having a central portion and two arms extending radially inwardly from the central portion, each radial arm exerting force on a separate one of the two sealing member radial wall sections so as to generate contact pressure between the sealing wall section and the rotary member flange. 
     
     
       9. The cartridge seal as recited in  claim 1  wherein:
 the rotary member flange has first and second opposing axial ends, the first end providing the radial sealing surface and the second end providing a radial contact surface facing generally away from the sealing surface; and 
 the collar has an axial portion and a radial portion extending radially inwardly from the axial portion, the collar radial portion being disposeable generally against the rotary member flange portion so as to form a secondary sealing interface. 
 
     
     
       10. The cartridge seal as recited in  claim 9  wherein the rotary sealing member is formed of a metallic material having a first hardness and the collar is formed of a metallic material having a second hardness, the second hardness being substantially lesser than the first hardness. 
     
     
       11. The cartridge seal as recited in  claim 1  wherein the collar is configured to axially retain the static sealing member within the casing. 
     
     
       12. The cartridge seal as recited in  claim 11  wherein the casing includes a radially inwardly extending section, the static sealing member has a radially outwardly extending flange, and the collar has a radial end surface disposable against the sealing member radial flange such that the sealing member flange is sandwiched between the collar and the casing radial section when the collar is coupled with the casing. 
     
     
       13. The cartridge seal as recited in  claim 12  wherein the casing has an axial portion with an inner circumferential surface, the radial portion extending inwardly from the axial portion, and the collar has an outer circumferential surface frictionally engageable with the casing inner circumferential surface so as to couple the collar with the casing. 
     
     
       14. The cartridge seal as recited in  claim 1  wherein:
 the rotary member flange has first and second opposing axial ends, the first end providing the radial sealing surface and the second end providing a generally radial contact surface facing generally away from the sealing surface; 
 the casing has an axial portion with an inner circumferential surface defining a bore and a radial portion extending radially inwardly from the axial section; and 
 the collar has an axial portion with an outer circumferential surface and a radial portion extending radially inwardly from the axial portion, the collar axial portion being disposeable within the casing bore such that the retainer outer circumferential surface is frictionally engageable with the casing inner circumferential surface to couple the collar with the casing, and the collar radial portion is spaced axially from the casing axial portion and is disposeable generally against the rotary member flange portion such that the rotary member is axially retained generally between the casing radial portion and the collar radial portion. 
 
     
     
       15. The cartridge seal as recited in  claim 14  wherein the casing axial portion has first and second opposing axial ends, the radial portion extending inwardly from the axial portion first end, and the casing further includes a retainer extending radially inwardly from the second end of the casing axial portion and engageable with the collar so as to axially retain the collar within the casing bore. 
     
     
       16. The cartridge seal as recited in  claim 14  wherein the rotary member is formed of a metallic material having a first hardness and the collar is formed of a metallic material having a second hardness, the second hardness being substantially lesser than the first hardness. 
     
     
       17. The cartridge seal as recited in  claim 1  wherein the casing has an outer circumferential surface frictionally engageable with the housing so as to couple the cartridge seal with the housing. 
     
     
       18. A cartridge seal for sealing a space between a housing having a bore and a shaft disposed at least partially within the housing bore and rotatable about a central axis, the cartridge seal comprising:
 a rotary sealing member having an inner circumferential surface defining a bore for receiving a portion of the shaft and a generally circular outer flange extending radially outwardly from and circumferentially about the central axis, the outer flange having a generally radial sealing surface; 
 a static seal assembly disposed about the rotary sealing member and including a generally annular casing coupleable with the housing, a generally annular static sealing member disposed within the casing and having a generally radial sealing surface sealingly engageable with the rotary member sealing surface so as to form a primary sealing interface, a biasing member configured to axially bias at least a portion of the static sealing member generally toward the rotary member flange, and a generally annular collar coupled with and disposed at least partially within the casing and configured to axially retain the rotary member within the casing such that the seal assembly is mountable on a shaft as a single unit; and 
 wherein the rotary member flange has first and second opposing axial ends, the first end providing the radial sealing surface and the second end providing a radial contact surface facing generally away from the sealing surface and the collar has an axial portion and a radial portion extending radially inwardly from the axial portion, the collar radial portion being disposeable generally against the rotary member flange portion so as to form a secondary sealing interface.